[supertrope]

While Eisenhower was inspired by the German autobahn, military use of roads was a sales talking point. The real reason for highways was to allow favored Americans to live in detached houses while still accessing city jobs. We could have it both ways!

Rail is a much more efficient way to move troops and equipment. Modern warfare requires lightning fast movement which means cargo planes. Eisenhower himself used a “New Look” policy of relying heavily on nuclear weapons so that the army could be scaled back.

[bumby]

After looking into a bit, I think you're right about the impetus of the national highway system. But, while rail is more efficient way to move materiel, it's also less flexible and more vulnerable. I think in that aspect, a highway system is probably preferable.